Comments on: The capitvating and deadly pyroclastic flow

The capitvating and deadly pyroclastic flow

baphomet — Wed, 18 Feb 2009 11:53:46 -0800

An erupting stratovolcano poses numerous hazards for nearby habitation, but none nearly so terrifying and deadly as the pyroclastic flow. Pyroclastic flows, comprised of tons of superheated sulfuric gases, particulate rock materials and ash, can reach temperatures of 1,830 °F and travel at alarming speeds up to 450mph. Convection of materials within the clouds causes them to become a suspension, fluidizing and thundering noxiously across the surrounding landscape for miles, in some cases even uphill or across open water. Wherever these clouds come in contact with humans the result is catastrophe, as the residents of Herculaneum and St. Pierre, Martinique learned within minutes of the eruptions of Vesuvius in 79AD and Pelee in 1902-- both towns were overwhelmed by pyroclastic clouds, igniting all flammable materials and incinerating and suffocating the inhabitants. None survived Herculaneum, while just two of St. Pierre's 26,000 survived, one of whom was a prisoner condemned to death and awaiting his execution in a dungeon cell. Despite their incredible capacity for violence, pyroclastic flows are also capable of producing mesmerizing, awe-inspiring beauty.

By: DU

DU — Wed, 18 Feb 2009 12:08:24 -0800

I was confused that the geology site doesn't mention Krakatoa, but I guess without pictures it didn't happen. (They do mention it elsewhere.) How did the tourist in that Japan video not run like mad? Or did Discover (or whoever) stitch more than one video together? Oh nice, the related videos have 911 conspiracists claiming that "only volcanoes and controlled demolition" exhibit pyroclastic flow.

By: adamvasco

adamvasco — Wed, 18 Feb 2009 12:27:42 -0800

Pictures of St Pierre after the eruption of 1902. Extract from "The Last Days of St Pierre".

By: George_Spiggott

George_Spiggott — Wed, 18 Feb 2009 12:30:51 -0800

just two of St. Pierre's 26,000 survived, one of whom was a prisoner condemned to death and awaiting his execution in a dungeon cell. Let me guess, his defense attorney asserted that society was to blame, and God agreed.

By: Artw

Artw — Wed, 18 Feb 2009 12:35:28 -0800

Pyroclastic flows - never want to be near one, but boy are they cool.

By: Inspector.Gadget

Inspector.Gadget — Wed, 18 Feb 2009 12:41:45 -0800

The GZA was unavailable for comment.

By: monju_bosatsu

monju_bosatsu — Wed, 18 Feb 2009 12:47:38 -0800

In January of 1981, National Geographic published a series of photographs taken by Robert Landsburg depicting the first lateral blast of the Mount St. Helens eruption. The photos distinctly showed the asymmetrical bulge immediately preceding the explosion, followed by the explosion itself, and the subsequent pyroclastic flow coming closer, closer, ever closer. Landsburg was killed, suffocated by the toxic cases emitted with the explosion, but not before he secreted his camera in his jacket in an effort to protect the film. A favorite professor of mine showed an introductory geology class that series of pictures, blown up on a screen 20 feet tall, without letting on about Landsburg's fate. The class began with the oohs and ahs typical of many students who see the dramatic pictures for the first time, but gradually fell silent towards the end of the series as they realized what must have happened. I wish I could find those photographs online.

By: elendil71

elendil71 — Wed, 18 Feb 2009 12:54:34 -0800

Cooool! Pyroclastic flows also create ignimbrite, a nifty type of rock that has been used for millennia by prehistoric folks as toolstone.

By: notsnot

notsnot — Wed, 18 Feb 2009 13:20:02 -0800

The lava dome at St. Pierre looks like a massive dick. Cool. (yes, I am twelve.)

By: greenland

greenland — Wed, 18 Feb 2009 13:40:53 -0800

Volcanoes, man...they send lava, earthquakes, tephra, mudslides, lightning storms, ash, and smothering blankets of gas to kill you, and if somehow you escape them, they just go ahead and chase you down. They're responsible for mass extinctions! I am eternally terrified of these things, which means I will probably die in one.

By: collocation

collocation — Wed, 18 Feb 2009 13:48:44 -0800

I live with a volcanologist who studies pyroclastic flows (among other volcanic processes). He always wins the "so what do you do" contest when we meet new people.

By: StickyCarpet

StickyCarpet — Wed, 18 Feb 2009 14:52:22 -0800

Didn't some guy in a titanium canoe once try to ride one? Or did I dream that?

By: Artw

Artw — Wed, 18 Feb 2009 15:02:22 -0800

Do titanium canoes come with a sidecar for a lion?

By: ceedee

ceedee — Wed, 18 Feb 2009 15:06:52 -0800

He always wins the "so what do you do" contest when we meet new people. You think that's bad? I have a friend who's an astronomer researching rocketry! =:o

By: MrMoonPie

MrMoonPie — Wed, 18 Feb 2009 16:02:22 -0800

Oh, yeah? I'm Mr. Active Volcano Explorer, himself.

By: five fresh fish

five fresh fish — Wed, 18 Feb 2009 18:09:00 -0800

Pyroclastic flows - never want to be near one, but boy are they ~~cool~~ the hot damn! FTFY.

By: Artw

Artw — Wed, 18 Feb 2009 19:16:26 -0800

Hot IS cool, man, y'dig?

By: adamvasco

adamvasco — Thu, 19 Feb 2009 05:01:39 -0800

Google books has decided to make all pages of "The Last Days of St. Pierre" unavailable. Here (pdf) is a report in the NYT including eyewitness report from Capt. of the Roddam.

By: adamvasco

adamvasco — Thu, 19 Feb 2009 05:06:18 -0800

Also Pliny (78/9 AD) describing eruption of Vesuvius in letters to Tacitus.